Eli5 If you shine a laser up in the sky for ~3 seconds, does the beam eventually fizzle out or does it keep going until it hits an object?
In: 5
Technically, as it moves through the sky, it is hitting objects. Our atmosphere is filled with molecules like oxygen and nitrogen, as well as gaseous water (even on a clear day) which reflect, absorb and refract the beam (bounce it around to put it in a really simple but not entirely accurate way). So it does “fizzle out” as it travels. In space, where this atmosphere doesn’t exist, it could travel much further. But even the most focused beams will expand and appear more dim the farther away you are, similar to a far away star that, while emitting a lot of powerful light, appears very dim.
Latest Answers